@pleonasm - Frankly, the public has a really skewed image of how these machines work. On TV they always show defibrillation as something that's done to get the heart started again. However, they aren't used like that in real life. They are used to get the heart to work properly by giving it a flat line so it can restart itself.
If the problem is that there is already a flat line, there's nothing a defibrillator can do and there are other things that need to be tried (like CPR and medications). I'd hate for an ordinary person who doesn't understand this to be able to just grab a public AED defibrillator and use it without any instruction.